think for disco shots you need some decent shutterspeeds, since you dont want alot of blurry stuff in your pic. As it will probably will be dark there, thats gonna be tricky. Probably need a flash and/or a lens with a small f-number (canon 50mm 1.8 for example)

i am using a canon eos 400D can anyone tell me how to set it to bulb exposure if it can be please. i understand it gives you control of the shutter by how long you hold the button but not sure where the setting is.
is it something that only comes into function when a remote is being used ?

when you turn the wheel to change the shutterspeed, just keep on turning (to longer shuttertimes) in the end it will say bulb.
Well, thats how it works on my 350D, but i think its pretty much the same.

the tripod is more for the fact that you can open the shutter longer, so you can get light trails and stuff from the firework. So keeping the shutter open for a longer time will give blur without the tripod.

ahhhhhh......listen to this trick:
set your camera on a tripod....set for about a 15 or 30 second exposure (depends on the frequency of fireworks being shot off) (bulb if REALLY slow) Take a piece of cardboard - spraypaint it completely black. Press the shutter button with the piece of cardboard in front of the lens (do not bump your camera) and as you see a shoot flying up in the air - remove the cardboard - capturing the 'ka-boom'. Then throw the cardboard back over the sense immidiately. This technique will give the illusion of several explosions at once.
You can play with the amount of explosions and the rockets before they explode. Its quite fun